Can i have swollen lymph nodes from pulling/pressing skin over it. how long will it be swollen by this cause?

Usually not: No, usually not...Unless if you really push or pull the area so hard that you hurt yourself so badly or create an open wound/skin irritation, infection or inflammation over the skin or the area--then the lymph node adjacent to the trauma can be swollen up due to the trauma. Reactive lymph node usually will be back to normal within a few-several days to a couple of weeks or so.

Monitoring Centers: Lymphatic system absorbs/carries things too big to go into the arteries/veins like bacteria eaten by white cells and digested food. Lymph nodes "taste" the lymph for anything bad like bacteria/viruses/cancers, etc. When it detects a problem, it alerts the immune system and your body reacts. They enlarge in response to the inflammation they create when they react. They shrink when all is well.